scholarly journals Notes on Insect Pests in Antigua

1913 ◽  
Vol 4 (1) ◽  
pp. 61-65 ◽  
Author(s):  
H. A. Ballou
Keyword(s):  
Insect Pests ◽  
Egg Laying ◽  
Adult Beetle ◽  
Dead Branch ◽  
The Dead

The principal object of my visit to Antigua, during December 1912, was to study an outbreak of the twig borer of limes which had been reported by the Superintendent of Agriculture from two localities in the island.At the time of my visit, owing to recent pruning, there were only occasionally infested branches to be seen, but these were in sufficient number to enable me to form a very good opinion of the nature of the attack and of the general habits of the insect.The attack on a lime branch apparently always begins on a small twig. I am not able to say whether the twig on or in which the egg is laid is dead or dying at the time of egg-laying ; but in every instance of attack observed by me, both in the field and in specimens forwarded, the twig has been found entirely eaten out, the dead interior connecting with the tunnel in the larger branch from which the twig springs. This branch is always more or less girdled by the tunnel of the grub. The girdling seems to be the first thing done by the grub after completing the destruction of the smaller twig and it results in the death of the branch beyond the point of the girdle. The tunnel does not circle the twig in such a manner as to cut it off completely, but the direction is rather in a spiral, so that as the injury to the branch becomes more and more felt, it breaks down and is usually left hanging. The entire grub and pupa stages are passed within this branch, the adult beetle only issuing from the dead branch some time after emerging from its pupal condition.

Increased boron concentrations of Scots pine foliage induced by green pruning

2002 ◽  
Vol 32 (8) ◽  
pp. 1434-1440
Author(s):  
Heikki Nuorteva
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Research Area ◽  
Dead Branch ◽  
The Mean ◽  
Pruning Residues ◽  
The Dead ◽  
One Year ◽  
Green Pruning

The responses of Scots pine (Pinus sylvestris L.) foliar boron (B) concentrations to artificial defoliation by green pruning were studied by examining sample trees for 3 years after the treatments. In winter, concentrations of boron in foliage were determined individually from needles on the lateral top shoots of 168 sample trees (at the beginning 2–8 m, at the end 4–10 m tall). To prevent the pruning residues from affecting the nutrition of the sample trees, all pruned branches were transported away from the research area. Before pruning, there were no differences in foliar B among the pruning classes. Reduction of the living crown by pruning (LCRP, % of the initial crown ratio) 50% or more increased the concentrations of foliar B drastically for 3 years. The increase was greatest in the largest trees with the highest LCRP (about 70%), where the mean concentrations of foliar B one year after pruning were nearly 180% higher than in the unpruned trees. Pruning of the dead branch whorls or only the few lowest living whorls did not affect the boron nutrition of the trees. In the current study, the ability of rapid and sufficiently large defoliation to increase B concentrations for several years in the Scots pine foliage was confirmed experimentally; earlier suggestions have been based on analyses made after defoliation. The potential suitability of green pruning is discussed as a method for improving the boron status of trees in boron-deficient areas.

Influence of colour on oviposition behaviour in green lacewing Chrysoperla zastrowi sillemi (Esben - Petersen) (Neuroptera: Chrysopidae)

ENTOMON ◽  
2020 ◽  
Vol 45 (1) ◽  
pp. 75-80
Author(s):  
Elango K ◽  
Jeyarajan Nelson S ◽  
Dinesh Kumar P
Keyword(s):  
Laboratory Experiment ◽  
Insect Pests ◽  
Egg Laying ◽  
Colour Preference ◽  
Green Lacewing ◽  
Insect Predator ◽  
Orange Colour ◽  
Indigo Blue ◽  
Beneficial Insect ◽  
Chrysoperla Zastrowi Sillemi

The Green lacewing, Chrysoperla zastrowi silleni (Esben-Peterson), also known as “aphidlion” is a beneficial insect predator of various insect pests. The laboratory experiment was conducted during 2018-19 to evaluate the substrate colour preference for egg laying by C. zastrowi sillemi. Egg receiving sheets were pasted with white, black, green, indigo blue, yellow, brown, violet, sky blue, pink, red and orange colour papers. Among all colours C. z. sillemi females preferred orange colour as a substrate for egg laying with maximum number of eggs (43.13/female/day) followed by red colour substrate (25.50 eggs/female/day). White and black were least preferred.

scholarly journals Influence of Plant Physical and Anatomical Characteristics on the Ovipositional Preference of Orius sauteri (Hemiptera: Anthocoridae)

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 326
Author(s):  
Liu Zhang ◽  
Zifang Qin ◽  
Pingping Liu ◽  
Yue Yin ◽  
Gary W. Felton ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Cover Crops ◽  
Insect Pests ◽  
Biological Control Agent ◽  
Stomatal Density ◽  
Control Agent ◽  
Egg Laying ◽  
Anatomical Characteristics ◽  
Ovipositional Preference ◽  
Lobularia Maritima

Natural enemies play an important role in managing insect pests. Orius sauteri (Poppius) (Hemiptera: Anthocoridae), a predator of many soft-body insects, is an important biological control agent in Asia. Understanding this predator’s egg-laying preferences and a habitat needs is important for its success in pest control. We investigated the plant acceptability and ovipositional preference of O. sauteri for coriander (Coriadrum sativum L., Apiales: Apiaceae), marigold (Tagetes erecta L., Asterales: Asteraceae), sweet alyssum (Lobularia maritima L., Brassicales: Brassicaceae), and alfalfa (Medicago sativa L., Fabales: Fabaceae), and focused on the effects of plant physical and anatomical characteristics on the ovipositional preference of O. sauteri. The results showed that O. sauteri can lay eggs on uninfested plants in the vegetative stage and their eggs hatched normally. Orius sauteri females prefer plants with high stomatal density, a large stomatal area, and fewer trichomes as oviposition hosts, and the depth of egg placement was determined by leaf thickness. Our studies suggested that O. sauteri females can select oviposition hosts and specific oviposition sites by assessing the structural qualities of plant surface. Coriander and marigold are potentially suitable host plants for O.sauteri. The results aid the selection of cover crops to enhance natural enemies in the fields.

scholarly journals RNAi-Mediated Knockdown of Tssk1 and Tektin1 Genes Impair Male Fertility in Bactrocera dorsalis

Insects ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 164 ◽  
Author(s):  
Summar Sohail ◽  
Kaleem Tariq ◽  
Weiwei Zheng ◽  
Muhammad Waqar Ali ◽  
Wei Peng ◽  
...  
Keyword(s):  
Male Sterility ◽  
Male Fertility ◽  
Insect Pests ◽  
Expression Profiles ◽  
Functional Characterization ◽  
Egg Laying ◽  
Bactrocera Dorsalis ◽  
Adult Males ◽  
Control Male ◽  
Mature Adult

The genetic-based sterile insect technique (SIT) is an effective and environmentally safe strategy to diminish populations of agricultural and horticultural insect pests. Functional characterization of genes related to male fertility can enhance the genetic-based SIT. Tssk1 has been involved to control male fertility in both mammals and insects. Moreover, Tektin1 has also been revealed to influence male fertility in both human and mammals. These findings suggested that Tssk1 and Tektin1 identified from Bactrocera dorsalis could be required for male fertility in B. dorsalis. In this study, expression profiles of these two genes were studied at different developmental stages and in various tissues of adult males. Remarkably, it was found that Tssk1 and Tektin1 were highly expressed in the testis of mature adult males of B. dorsalis. Furthermore, Tssk1 and Tektin1 genes were downregulated by using the RNA interference (RNAi) method. Fertility assays including egg laying, hatching, and spermatozoa count were also performed to investigate male fertility of B. dorsalis. Results showed that knockdown of Tssk1 and Tektin1 caused male sterility up to 58.99% and 64.49%, respectively. As expected, the total numbers of spermatozoa were also significantly reduced by 65.83% and 73.9%, respectively. These results suggested that male sterility was happened wing to the low number of spermatozoa. In conclusion, we demonstrate that Tssk1 and Tektin1 are the novel agents that could be used to enhance the genetic-based SIT, or their double-stranded RNA (dsRNA) can be used as biopesticides to control the population of B. dorsalis.

Oviposition Deterrance Activity in Some Lamiaceae Plants against Some Insect Pests

1981 ◽  
Vol 36 (1-2) ◽  
pp. 122-125 ◽  
Author(s):  
R. N. Sharma ◽  
Vijaya Joshi ◽  
Geeta Zadu ◽  
A. S. Bhosale ◽  
A. S. Gupta ◽  
...  
Keyword(s):  
Potato Tuber ◽  
Plant Extract ◽  
Insect Pests ◽  
Egg Laying ◽  
Repellent Activity ◽  
Potato Tuber Moth ◽  
Pest Species ◽  
Acetone Extracts ◽  
Repellent Action

Abstract Acetone extracts of 9 out of 12 plants of Lamiaceae family exhibited high oviposition deterrance (OD) activity against the potato tuber moth, P. operculella (PTM) 4 of these completely prevented egg laying by the latter and A. aegypti. In case of PTM this activity persisted for a varying number of days. 3 of them were also active against D. koenigii and M. domestica. None of the active extracts showed significant antifeedant or repellent activity against any pest species except D. koenigii. It was concluded that except in the case of the latter, the OD activity exhibited was not a corollary of antifeedant or repellent action, as is usually presumed. Magnitude and persistence of OD activity of at least one plant extract against the PTM was considered sufficient for employment in insectistatic management of this pest.

Optimizing methods for rearing mated queens and establishing new colony of Oecophylla longinoda (Hymenoptera: Formicidae)

2017 ◽  
Vol 37 (04) ◽  
pp. 217-224 ◽  
Author(s):  
Rozalia G. Rwegasira ◽  
Maulid W. Mwatawala ◽  
Gration M. Rwegasira ◽  
Jörgen Axelsen
Keyword(s):  
Insect Pests ◽  
Colony Growth ◽  
Egg Laying ◽  
Direct Access ◽  
Effective Control ◽  
Sugar Solution ◽  
Oecophylla Longinoda ◽  
Access To Water ◽  
Rearing Methods ◽  
Different Sources

Abstract Oecophylla spp. are used as biocontrol agents for many types of insect pests. A large and stable population is essential for effective control of pests. Colonies of Oecophylla spp. can be transplanted from wild habitats into orchards. Transplanted colonies can only survive in the presence of egg laying queens. It is difficult to locate nests with egg laying queens in large colonies that may sometimes contain more than 100 nests. Therefore, the need to explore and develop methods for rearing newly mated queens in nurseries may not be over emphasized, hence the current study. In the first experiment, we tested three rearing methods on queen survival and colony establishment. In the second experiment, we compared feeding techniques of different weaver ants on young colony growth. We observed that queens were best reared under continuous, indirect access to water. The first workers emerged earlier (32 days on average) in indirect and direct continuous access to water methods than on limited access to water (sprinkled) (38 days on average). Moreover, rearing mated queens under continuous indirect access and continuous direct access to water methods saved labour and time, because of limited attendance to the colonies. Availability of water, sugar solution and different sources of protein throughout improved the growth of young colonies. Likewise, the number of workers increased rapidly. Therefore rearing mated queens in nurseries is possible and would minimize hustles in hunting for the colonies and their queens in the wilderness.

scholarly journals The predatory bug Orius strigicollis shows a preference for egg-laying sites based on plant topography

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11818
Author(s):  
Chendi Yu ◽  
Jun Huang ◽  
Xiaoyun Ren ◽  
G Mandela Fernández-Grandon ◽  
Xiaowei Li ◽  
...  
Keyword(s):  
Insect Pests ◽  
Southern China ◽  
Oviposition Behavior ◽  
Egg Laying ◽  
Oviposition Site ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Wide Range ◽  
Orius Strigicollis ◽  
Oviposition Sites

Background Oviposition site selection is an important factor in determining the success of insect populations. Orius spp. are widely used in the biological control of a wide range of soft-bodied insect pests such as thrips, aphids, and mites. Orius strigicollis (Heteroptera: Anthocoridae) is the dominant Orius species in southern China; however, what factor drives its selection of an oviposition site after mating currently remains unknown. Methods Here, kidney bean pods (KBPs) were chosen as the oviposition substrate, and choice and nonchoice experiments were conducted to determine the preferences concerning oviposition sites on the KBPs of O. strigicollis. The mechanism of oviposition behavior was revealed through observation and measurement of oviposition action, the egg hatching rate, and the oviposition time. Results We found that O. strigicollis preferred the seams of the pods for oviposition, especially the seams at the tips of the KBPs. Choice and nonchoice experiments showed that females did not lay eggs when the KBP tail parts were unavailable. The rates of egg hatching on different KBP parts were not significantly different, but the time required for females to lay eggs on the tip seam was significantly lower. Decreased oviposition time is achieved on the tip seam because the insect can exploit support points found there and gain leverage for insertion of the ovipositor. Discussion The preferences for oviposition sites of O. strigicollis are significantly influenced by the topography of the KBP surface. Revealing such behavior and mechanisms will provide an important scientific basis for the mass rearing of predatory bugs.

scholarly journals A thrips vector of tomato spotted wilt virus responds to tomato acylsugar chemical diversity with reduced oviposition and virus inoculation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sulley Ben-Mahmoud ◽  
Taylor Anderson ◽  
Thomas M. Chappell ◽  
John R. Smeda ◽  
Martha A. Mutschler ◽  
...  
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Frankliniella Occidentalis ◽  
Insect Pests ◽  
Western Flower Thrips ◽  
Egg Laying ◽  
Chemical Diversity ◽  
Flower Thrips ◽  
Type Iv ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

AbstractThere is increasing evidence that acylsugars deter insect pests and plant virus vectors, including the western flower thrips (WFT), Frankliniella occidentalis (Pergande), vector of tomato spotted wilt virus (TSWV). Acylsugars are sugar-polyesters composed of saturated, un-saturated, and variously branched short and long chain fatty acids (FAs) esterified to a glucose (acylglucose) or sucrose (acylsucrose) moiety. We sought to understand how acylsucrose amount and composition of associated FA profiles interacted to mediate resistance to WFT oviposition and TSWV inoculation on tomato leaves. Towards this goal, we examined WFT oviposition and TSWV inoculation behavior on tomato lines bred to exude varying amounts of acylsucrose in association with diverse FA profiles. Our data show that as acylsucrose amounts increased, WFT egg-laying (oviposition) decreased and TSWV inoculation was suppressed. Western flower thrips also responded to FA profiles that included iC4, iC11, nC12 and nC10 FA. These findings support improving acylsugar-mediated resistance against WFT by breeding tomatoes exuding greater amounts of acylsucrose associated with specific FA profiles. We show that increasing acylsucrose amount output by type IV trichomes and selecting for particular FA profiles through advanced breeding profoundly affects WFT behavior in ways that benefit management of WFT as direct pests and as TSWV vectors.

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