scholarly journals Using a Two-Sex Life Table Tool to Calculate the Fitness of Orius strigicollis as a Predator of Pectinophora gossypiella

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 275 ◽  
Author(s):  
Shahzaib Ali ◽  
Sizhe Li ◽  
Waqar Jaleel ◽  
Muhammad Musa Khan ◽  
Jintao Wang ◽  
...  

A two-sex life table is a useful tool for studying the fitness of predators. Previous studies of Orius strigicollis Poppius (Heteroptera: Anthocoridae) fitness have not been done on Pectinophora gossypiella (Lepidoptera: Gelechiidae) using a two-sex life table tool. This study reports the fitness of the minute predatory flower bug, O. strigicollis when feeding on the cotton pest P. gossypiella using a two-sex life table tool. Different densities (5, 10, and 15 eggs) of P. gossypiella eggs were used to calculate the feeding capacity and fitness of O. strigicollis in the laboratory at 28 °C ± 1, 75 ± 5% RH and 16:8 (L:D). The results concluded that O. strigicollis is an efficient predator of P. gossypiella. The maximum growth capacity of the predatory bug O. strigicollis was attained when it was fed on 10 and 15 P. gossypiella eggs. Furthermore, shorter generation and development time were also observed in the case of 15 eggs of P. gossypiella. These results suggest that O. strigicollis has considerable predatory potential and prefers feeding on P. gossypiella eggs than on the first instar larvae at the fourth instar or the female stage. Although the field potential of O. strigicollis is still unknown, this study will support future investigations in terms of field applications.

2009 ◽  
Vol 54 (2) ◽  
pp. 135-142
Author(s):  
A.K. Musa ◽  
M.C. Dike

The life cycle of the Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on stored groundnut was studied under fluctuating laboratory conditions of 25?5?C and 70?5% relative humidity. There were five larval instars and the total development time from egg to adult ranged from 37 to 40 days with an average of 37.95 days. The duration of each developmental stage was egg: 6.05 days; first instar: 3.8 days; second instar: 4.7 days; third instar: 5.6 days; fourth instar: 6.2 days; fifth instar: 6.8 days and pupa: 4.8 days. Females had an average fecundity of 80.2 eggs. Mean adult longevity was 12.4 days. .


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9594
Author(s):  
Shahzaib Ali ◽  
Qian Zhu ◽  
Waqar Jaleel ◽  
Shakeel Ur Rehman ◽  
Muhammad Asim Rasheed ◽  
...  

Background Pink bollworm (Pectinophora gossypiella) is a destructive insect pest of cotton crops in China and globally, which is actively predated on by Orius strigicollis. Studies on the fitness or survival of O. strigicollis fed on P. gossypiella at different temperatures have not been reported. The fitness of O. strigicollis may be well explained using two-sex life table parameters. Thus, the present study provides important insights for the effective biocontrol of P. gossypiella. Methodology Considering the importance of fitness parameters and biocontrol, the present study explores the feeding potential and age-stage, two-sex life table traits of O. strigicollis on P. gossypiella eggs at different temperatures (24, 28 and 32 °C) in the laboratory. Results The intrinsic rate of increase (r) was higher at 28 °C (0.14 d−1) than at 24 °C (0.0052 d−1) and 32 °C (0.12 d−1). Similarly, the net reproductive rate (R0) was higher at 28 °C (17.63 offspring) than at 24 °C (1.13 offspring) and 32 °C (10.23 offspring). This concluded that the maximum feeding potential and growth capacity of O. strigicollis could be attained at 28 °C when fed on P. gossypiella eggs. O. strigicollis adults preferred to feed on P. gossypiella eggs compared with first instar larvae. Based on these results, the present study suggests that O. strigicollis represents a promising biological control agent against P. gossypiella eggs in cotton fields.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.


2020 ◽  
Vol 17 (2) ◽  
pp. 104
Author(s):  
Dosma Ulina Simbolon ◽  
Maryani Cyccu Tobing ◽  
Darma Bakti

<p><em>Stenocranus pacificus </em>Kirkaldy (Hemiptera: Delphacidae) is destructive pest on corn plants in South Lampung and it has been reported to cause corn damages in North Sumatra. The  objective of this research was to study some aspects biology of <em>S. pacificus</em> on corn plants in screenhouse. The research was conducted by observing the biology of <em>S. pacificus</em> that was reared on corn plants in screenhouse.<em> </em>The results showed that life cycle of <em>S. pacificus </em>was 38–47 (41,60 ± 3,19) days: egg was 9–11 (10,20 ± 0,79) days, the first instar nymph was 3–4 (3,70 ± 0,48) days, the second instar nymph was 3–4 (3,90 ± 0,32) days, the third instar nymph was 3–4 (3,70 ± 0,48) days, the fourth instar nymph was 3–4 (3,80 ± 0,42) days, and the fifth instar nymph was 3–4 (3,60 ± 0,52) days. Age of female was 13–17 (15,30 ± 1,34) days. It was longer than age of male which was 8–12 (10,10 ± 1,20) days. Female could produce 181–214 (197,60 ± 11,64) eggs during its life. The sex ratio was 1:1,98.</p>


1951 ◽  
Vol 42 (2) ◽  
pp. 355-370 ◽  
Author(s):  
J. Muspratt

Living specimens of Megarhinus brevipalpis were transported from southern Natal to Johannesburg to establish an insectary-bred colony. The natural habitat of these predatory mosquitos consisted of small isolated patches of sub-tropical forest, in which the rainfall is 40–50 ins. (102–127 cm.) with a mean winter temperature of 64°F. (17·7°C.) and an annual range of 27°–33°F. (15°–18°C). The breeding places were leaf axils of Strelitzia nicolai (a plant resembling a wild banana), small rot holes in trees and larger ones in Strelitzia stumps. The larvae were collected from leaf axils with an apparatus consisting of a rubber bulb to which were attached lengths of glass and rubber tubing.The insectary was a room 9 ft.×8 ft. 6 ins. and 9 ft. high which was kept at tropical heat and humidity. Mating of the adults was observed, copulation being effected while at rest or in flight. Oviposition was usually accomplished in flight but also while at rest on the surface of the water. In the summer time two females, which were tested, laid about 85 eggs each during the month following emergence from the pupa, six or seven days elapsing after emergence before the first oviposition. In the middle of the winter, oviposition (with later generations) became very irregular in spite of the temperature and humidity remaining constant. The adults, which were comparable to those of the natural habitat, were fed on sugar solution, honey and fruit juice. One bred out as a gynandromorph.When given an abundant supply of larvae of laboratory bred Aëdes aegypti, the life-cycle of M. brevipalpis was normally : egg (incubation), less than two days ; larva, 11–20 days (average 14·5 days) ; pupa, five days. This does not include a small number of exceptional cases in which the life as a fully grown larva was abnormally prolonged (in one case nearly four months) for reasons which are not absolutely clear. The larvae killed from 100 to 200 or more Aëdes larvae during the normal larval life, but many of these were not eaten when the brevipalpis were in the late fourth instar. By a special technique they were also induced to eat dead tissues including minced pork brawn, minced maggots and minced flies. Except for the latter these were not satisfactory foods although there was slow development.Fourth-instar larvae were kept out of water for three to four weeks (without food), in a damp atmosphere, and afterwards when fed most of them developed normally, but pupation was sometimes suspended for a considerable time. They have been sent by post (out of water) in tubes with damp cotton wool and filter paper.The egg differed from that of other Megarhinus species in having a crown of projections at one end with a cup-like structure in the centre. The exochorion had roughly hexagonal cells but without numerous tubercles as in other species.First-instar larvae remained in the egg-shell after hatching when the eggs-were out of water but on a damp surface and in a saturated atmosphere. They survived like this for up to six days or about the same time as the larvae survived in tap water if there was no food. When liberated in water the head of the first-instar larva was comparatively small with the mouth parts folded in. Within two hours of liberation in water the head enlarged considerably and the mouth parts came into position ; the larva was then ready to catch its Culicine prey. When in water containing dead leaves, these larvae survived from a few days to over four weeks and some grew to the third instar without any Culicine food.Cannibalism was investigated. Fourth-instar larvae did not attack each other readily ; they devoured smaller larvae of their own species and small to medium size larvae resorted to cannibalism, particularly in the absence of Culicine prey. There was evidence that fourth-instar Aëdes aegypti occasionally ate first-instar Megarhinus.The discussion traces attempts which have been made in certain Pacific islands, notably Hawaii and Fiji, to use Megarhines for biological control of disease-carrying mosquitos. M. brevipalpis has a shorter life-cycle than the species introduced into these islands and the conclusion reached is that laboratory breeding, to enable large numbers to be released in certain areas, would be a suitable adjunct to a programme of general control, in this part of the world. Airmail consignments of larvae are being sent to Hawaii with the object of starting a laboratory colony there.


1970 ◽  
Vol 15 ◽  
pp. 1-5 ◽  
Author(s):  
GC Biswas ◽  
W Islam ◽  
MM Haque

The duration of hatching, larval instars and pupal stages of Stethorus punctillum feeding on two-spotted spider mite, Tetranychus urticae were investigated in different seasons under laboratory conditions. The highest values of different developmental stages were obtained during winter. Higher temperature significantly reduced the duration of different developmental stages. No significant effect of relative humidity was exerted on the development stages of S. punctillum. The predation rate of fourth instar larva of S. punctillum was the highest whereas the first instar larva consumed the lowest number of prey. The fourth instar larva of the predator consumed 135.8 eggs, 126.4 larvae, 96.6 nymphs and 72.8 adults per day separately. But the first instar consumed 41.6 eggs, 36.2 larvae, 26.8 nymphs and 16.8 adults during the same period. Keywords: Developmental durations, predation, Tetranychus urticae, Stethorus punctillum   doi: 10.3329/jbs.v15i0.2196 J. bio-sci. 15: 1-5, 2007


1985 ◽  
Vol 6 (2) ◽  
pp. 177-181 ◽  
Author(s):  
D. A. Enobakhare

AbstractThe biology of the aphid, Cerataphis variabilis H.R.L., on Raphia hookeri Mann & Wendl., was studied in the laboratory and the field using a ‘clip-on’ cage and a sleeve cage. The first instar lasted 5.1 days. The second and third instars each lasted 2.45 days, while the fourth instar lasted 2.4 days. The total developmental period of the nymphs was 11.3 days at 26.4 ± 1.43°C and r.h. 83 ± 1.46%; 11.6 days at 26.4 ± 1.63°C and r.h. 85 ± 1.19%; 12.9 days at 27.9 ± 1.04°C and r.h. 75.5 ± 1.64%; 12.95 days at 27.8 ± 0.33°C and r.h. 69 ± 1.23%; 15 days at 21.4 ± 0.58°C and r.h. 45 ± 1.77%. These periods were significantly different at 5% level (LSD = 0.59 days). The higher the temperature and relative humidity the shorter the developmental period (with temperature: r = −0.69, 20.8–28.9°C; r.h.: r = −0.97, 43.2–86.2%). The number of progeny per adult ranged from 54 to 60 in a period of 28–31 days. The longevity ranged from 31 to 34 days.


2019 ◽  
Vol 57 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J Alejandro Martínez-Ibarra ◽  
Tzintli Meraz-Medina ◽  
Benjamin Nogueda-Torres ◽  
María E Villagrán-Herrera ◽  
Jose A de Diego-Cabrera

Abstract This study reports the third collection of Triatoma nitida Usinger in Mexico, with a brief description of the collection area and an investigation of parameters related to its vectorial capacity. Whether a triatomine (Hemiptera: Reduviidae) species is a primary or secondary vector is determined by factors that include vectorial capacity, anthropophilic habits, geographic distribution, and capacity to invade and colonize human dwellings. However, when the primary vectors are removed, secondary vectors, such as T. nitida, can become important transmitters of Trypanosoma cruzi Chagas to humans. To estimate the vectorial capacity of T. nitida, the egg-to-adult development time, number of blood meals required to molt to the adult stage, accumulative mortality, onset time for feeding, and feeding and defecation times were examined. Triatoma nitida (n = 100) required a median of 590 d to complete its development time, with a median of 31 blood meals. Almost half (46.5%) of the nymphs died during the cycle. The onset of feeding time exceeded 5 min in all nymphal instars (except on fourth-instar) and adults and feeding times exceeded 22 min in all instars, except on first-instar nymphs. No defecation was observed for 65.6% (n = 383) of the triatomines during a 30-min observation period. Based on the six parameters, the vectorial capacity of T. nitida should be considered as low. However, surveillance programs should include this species because the potential importance of T. nitida as a vector has been demonstrated in other countries.


1972 ◽  
Vol 104 (6) ◽  
pp. 797-814 ◽  
Author(s):  
Robert G. Helgesen ◽  
Dean L. Haynes

AbstractThe cereal leaf beetle, Oulema melanopus (L.), has rapidly increased its numbers and range since it was discovered in Michigan in 1962. We have shown in this report that intraspecific density-dependent mortality is the major constraint on survivorship. We have attempted to quantify survival within a generation from the egg stage to the adult.Larval mortality varies among populations. Density-dependent mortality, caused by intraspecific competition, accounts for most of the variation of within-generation survival of the cereal leaf beetle in wheat and oats. Mortality in the first instar on oats and the fourth instar on wheat and oats is a linear function of the logarithm of total egg density. Establishment of the first instar on oats appears to become more difficult as density increases because leaf surface disturbance and interference with larger larva increases. Competition for food accounts for the increase in mortality of the fourth instar in both wheat and oats as density increases. Egg survival, survival of the first instar on wheat and in the second, third, and pupal stage in both crops are constants with respect to density. These constants can be expected to change with respect to other environmental parameters however, e.g. host variety, planting date, rainfall, etc.


1971 ◽  
Vol 103 (11) ◽  
pp. 1495-1503 ◽  
Author(s):  
H. S. Whitney

AbstractThe physical association between Dendroctonus ponderosae Hopk. and its associated blue stain fungi Ceratocystis montia Rumb. and Europhium clavigerum Robinson and Davidson and the yeasts Pichia pini (Holst) Phaff, Hansenula capsulata Wickerham, and H. holstii Wickerham is described in single broods reared in bolts of lodgepole pine, Pinus contorta Dougl. var. latifolia Engelm. Eggs just prior to hatch and first-instar larvae were always in contact with the microorganisms whereas newly laid eggs, second-, third-, and fourth-instar larvae were not. During pupation, blue stain fungi and yeasts colonized pupal chamber walls. Transfer of these microorganisms to the new generation of insects was ensured when tenerals contacted the microorganisms lining the pupal chamber. Ensured physical contact between these organisms supports the hypothesis of a symbiosis between them.


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