THE BIOLOGY OF NEODIPRION NIGROSCUTUM (HYMENOPTERA: DIPRIONIDAE) IN WISCONSIN

1967 ◽  
Vol 99 (2) ◽  
pp. 146-159 ◽  
Author(s):  
G. C. Becker ◽  
D. M. Benjamin

AbstractThe specific status of Neodiprion nigroscutum Middleton is firmly established by new data. The adult female is mostly black and brown. The second annulus of the lancet is generally weakly developed ventrally. The larvae have black head capsules in the first instar, but this coloration usually changes to reddish brown in the later instars. The third, fourth, and fifth feeding-instar larvae have unbroken subdorsal and supraspiracular lines, and broken postepipleural lines, but lack an epiproctal spot. The nonfeeding-instar larvae often have a pink body color. The egg mass of most females is green. Jack pine is the preferred host. The fecundity is approximately 100 eggs, but they are typically distributed over many branches, usually in one needle on each branch. Larval colonies composed of first- through fourth-instar larvae usually contain 3–10 larvae, while colonies of fifth-instar larvae usually contain 1–6 larvae. There are two generations per year in southern Wisconsin. Feeding-instar larvae are present in late May and June, and again (second generation) in August and September. The species is distributed throughout the jack pine stands of Wisconsin. Phenological data and notes on parasites are presented.

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>


1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.


2010 ◽  
Vol 19 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Huarrisson Azevedo Santos ◽  
Isabele da Costa Angelo ◽  
Marcos Pinheiro Franque ◽  
Usha Vashist ◽  
Aline Falqueto Duarte ◽  
...  

The current study investigated the biology of nymphs of the first and second instars of Argas (Persicargas) miniatus. Nymphs were deprived of food for 15, 30 or 60 days and held at 27 ± 1 ºC and 80 ± 10% relative humidity (controlled conditions) or at room conditions of temperature and relative humidity. Nymphs of first instar deprived of food for 15 or 30 days molted to second and third instars in both controlled and room conditions. Nymphs of the first instar deprived of food for 60 days had 28 and 37% mortality in controlled and room conditions, respectively; and survivors did not attach to the host. Nymphs of the second instar, deprived of food for 60 days, molted either to the third instar or to males after feeding on Gallus gallus, and the nymphs of the third instar developed to adults (42.42% males and 36.36% females when nymphs were held in controlled temperature and humidity conditions, and 40.54% males and 48.65% females when nymphs were held in room conditions). The remainder of the nymphs molted to the fourth instar and then molted to females. In conclusion, the nymphal starvation period of 60 days determined the number of nymph instars in the life cycle of A. miniatus under the experimental conditions studied.


1963 ◽  
Vol 95 (8) ◽  
pp. 813-820 ◽  
Author(s):  
D. G. Harcourt

AbstractCounts of the Colorado potato beetle on potato did not conform to the Poisson distribution, there being an excess of uninfested and highly infested hills over the expected numbers. However, when observed distributions were fitted to the negative binomial series, the discrepancies were not significant when tested by chi-square. The negative binomial parameterktended to increase with density. Using a commonk, the distribution of the various stages may be described by expansion of (q−px)−k, when values ofkare as follows: adult, 1.95; egg mass, 4.10; first instar, 0.68; second instar, 0.78; third instar, 1.04; fourth instar, 1.07.For all stages, the variance was proportional to a fractional power of the mean. Use of the individual potato stalk as a sample unit had little effect on the skewness of the distribution. Four transformations are offered for stabilizing the variance of field counts.


2003 ◽  
Vol 38 (4) ◽  
pp. 519-524 ◽  
Author(s):  
Gan Ming ◽  
Miao Xue Xia ◽  
Zhu Xiang-Xiong ◽  
Ding De Cheng

The developmental stages of a solitary parasitoid, Lysiphlebus japonicus Ashmead, of the black bean aphid, Aphis craccivora Koch, were described by using light and scanning electron microscopy. Lysiphlebus japonicus has four larval instars. The first instar is mandibulate, caudate and has sclerotized spines. Supernumerary neonates are eliminated by powerful mandibles of the first hatched larva. The second instar has degenerative mandibles and is covered with small sclerotized bristles on abdominal segments; the cauda is short and blunt. The third instar is mandibulate; its cuticle is smooth and the caudal segment retrogresses to a short salient. The fourth instar is strong and hymenopteriform; their mandibles are smaller than those of the third instar, and various sensory organs are well developed, especially for the mouthpart.


1991 ◽  
Vol 123 (3) ◽  
pp. 601-609 ◽  
Author(s):  
J.C. Cunningham ◽  
W.J. Kaupp ◽  
G.M. Howse

AbstractA double application of Disparvirus, a nuclear polyhidrosis virus, at 1.25 × 1012 polyhedral inclusion bodies (PIB) per hectare, giving a total of 2.5 × 1012 PIB per hectare, was applied aerially on three plots in an emitted volume of 10.0 L per hectare. The two applications were 3 days apart and most larvae were in the first instar. Three plots were selected as untreated checks; each was paired with a treated plot on the basis of pre-spray gypsy moth egg-mass numbers and locality. The pre-spray egg-mass counts ranged from 1430 to 8520 per hectare in the six plots. Assessment of the treatment was based on numbers of pupae and fall egg masses as well as on estimates of defoliation and on microscopic examination of larvae collected at weekly intervals to determine the incidence of virus infection. Between 12 and 19 days post-spray, 49, 61, and 85% of the larvae were infected with virus in the three treated plots compared with 3, 7, and 14%, respectively, of larvae in the check plots. Red oak was 14% defoliated in two of the treated plots compared with 82 and 90% in their corresponding check plots. The third plot suffered 46% defoliation due to leaf-eating caterpillars other than gypsy moth; defoliation in its corresponding check plot was 31%. Reductions in egg-mass numbers in the treated plots were 76, 93, and 98% compared with an increase of 56% and decreases of 50 and 70%, respectively, in corresponding check plots. Corrected population reductions (Abbott’s formula) were 84, 85, and 92% in the three treated plots.


1966 ◽  
Vol 57 (1) ◽  
pp. 121-136 ◽  
Author(s):  
U. S. Srivastava ◽  
S. B. Agarwal

Anjeerodiplosis peshawarensis Mani is a serious pest in North India of the fruit of the country fig (Ficus carica), which is its only known host. The midges are abundant, hovering under the host tree in the mornings and at dusk, and breed throughout the year, except in the summer from April until the July rains. In this period newly formed fruits are not infested, but in other months scarcely 30 per cent, of the fruits remain free from attack.Eggs are laid in fruits when they one week old, succulent, and of the size of a pea. The eggs are minute, hyaline, unsculptured, oval and pedicellate and occur in bundles of 16. Incubation takes three days in September and March and five days in December and January. In laboratory tests, average viability in January was found to be about 83 per cent.The entire larval period is passed inside the figs, each of which may contain 200–300 larvae. There are four larval instars, which differ in size according to Dyar's law and in morphology. The first-instar larva is devoid of cuticular outgrowths and does not show spiracles; the second and third instars have nine pairs of spiracles and possess characteristic spines, warts and tubercles; the fourth instar develops the sternal spatula. The entire larval period lasts three weeks from the middle of August to October and four weeks in January and February. From the middle of April until the July rains, fourth-instar larvae remain inside the figs. When the larval period is three weeks, the first and second instars together and the third and fourth instars separately last about a week.Full-grown fourth-instar larvae bore out of the fruit and drop to the ground, where they jump for some time with the aid of their sternal spatula. They finally pupate in the soil without forming a cocoon but become covered in a protective case composed of soil particles that adhere to the larval skin. Early fourth-instar larvae, which do not have a sternal spatula, if taken from the fruits, may also successfully pupate, and the pupal period is normal. This period is 10–15 days between July and November and 25–26 days in January and February. It is shortest (10 days) in the rainy season, when both temperature and humidity are high.The pupa is obtect, creamy white and bears poorly developed cephalic horns and bristles, well developed thoracic horns and many spines and cuticular outgrowths. Mortality in the pupal stage is between 15 and 30 per cent.Emergence of the adults invariably occurs in the early hours of the day. Two or three days before emergence, the protective case becomes detached piecemeal. Males emerge before females. The ratio of males to females on the day of emergence is 1:2 between March and December and 2:3 in January and February. Copulation starts soon after emergence and lasts from 60 to 90 seconds.There is considerable overlapping of generations. On the basis of the time required for completion of the life-cycle in different months, it is calculated that seven generations are completed in a year.


1976 ◽  
Vol 6 (4) ◽  
pp. 478-486 ◽  
Author(s):  
H. A. Bolghari

Multiple regression equations have been developed to predict yield from young red pine and jack pine plantations. Data from 446 sample plots representing young red pine and jack pine stands located on the south shore of the St. Lawrence River between Quebec and Montreal were analysed. The red pine plantation yielded more than the jack pine. However, in plantation both species yield more than in natural stands. Taking into account the age and spacing of the sampled plantations, the equation obtained can provide information on yield of red pine and jack pine stands the maximum spacing of which is 3 × 3 m, up to the age of 45 and 35 years respectively. The equations will allow the construction of preliminary yield tables for both species.


2014 ◽  
Vol 97 (1) ◽  
pp. 277-280 ◽  
Author(s):  
Giulianne S. Calizotti ◽  
Antônio R. Panizzi
Keyword(s):  
Egg Mass ◽  

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