Density-Dependent Mortality of the Diving Beetle, Rhantus elevatus (Dytiscidae: Coleoptera) Preyed Upon Culex pipiens Larvae: Effects of Prey and Predator Densities.

Diving beetles (Coleoptera: Dytiscidae) are general predators that feed primarily on mosquito larvae and can control their populations, but the evidence for such an assumption remains weak. Rhantus elevatus is an important predator of this group distributed in Egypt with both larval and adult stages preying on immature mosquito. For determine predator effectiveness, it is requisite to identify the functional response (a = rate of attack and T= time of handling) and searching efficacy (a= area of discovery and m = mutual interference) as both correlate with biocontrol efficacy.

Measuring the Costs of Limb Regeneration and Their Transgenerational Consequences in Two Nearctic Lady Beetles (Coleoptera: Coccinellidae).

We examined the ability of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville to regenerate, during pupation, a foreleg amputated in the fourth instar. Leg regeneration was complete for 80.7% of amputated H.

Validation of degree-day models for predicting the emergence of two fruit flies (Diptera: Tephritidae) in northeast Egypt.

We estimated thermal developmental thresholds (T ) and degree-day (DD) constants for the immature stages of two tephritid pests, Bactrocera zonata (Saunders) and Ceratitis capitata (Weidenmann). Males of both species were trapped in an Egyptian guava orchard during the fruiting seasons of 2016 and 2017 and trap catches were compared with peak flights predicted by the DD model based on local weather data. Ceratitis capitata had faster development than B.

Fitness costs of reflex bleeding in the ladybird beetle Harmonia axyridis: the role of parental effects.

Reflex bleeding is an important antipredator defense mechanism in Coccinellidae. We examined the costs of reflex bleeding in larval and adult stages of the ladybird beetle Harmonia axyridis on offspring fitness and reproductive performance through the comparisons between bled and control larvae, reciprocal crosses of bled/control beetles, and early and late clutch phenotypes. Beetles bled during their larval stage spent a longer time in development and weighed less than controls.

Improving the Lifetime Efficiency of Trimedlure-Dispensing System in Trapping the Fruit Fly Ceratitis capitata Using Polyethylene Matrix.

Detection of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is highly reliant on traps loaded with trimedlure (TML), a male-specific attractant. The successful application of attractants requires that constituents are placed in a suitable dispensing system to reduce volatilization and increase the effective field longevity of the attractant. A series of trials were conducted in different fruit orchards to test 1) the efficiency of a polyethylene-matrix plug in regulating the emission rate of TML 2) and the lifetime attractiveness of the plug compared to the cotton wick dispenser.

Limb Regeneration and Interference Competition Consequences on Foraging Efficiency of Coccinella undecimpunctata and Hippodamia variegata (Coccinellidae: Coleoptera) to Their Prey, Aphis craccivora (Hemiptera: Aphididae).

Regeneration of limbs lost during development has been recorded in a large number of species of hexapoda including many Coccinellids. Although regeneration has obvious survival and fitness benefits, it has also been demonstrated to impose costs on development, reproduction, and behavior. To investigate consequences of regeneration on foraging behavior, Coccinella undecimpunctata L.

A Life Table for Liriomyza trifolii (Diptera: Agromyzidae) in a Temperate Zone of Northeast Egypt With Key Factor Analysis.

The American serpentine leaf miner, Liriomyza trifolii (Burgess) (Diptera: Agromyzidae), is a perennial pest of leguminous crops in the Mediterranean region. A life table was constructed for L. trifolii infesting broad bean, Vicia faba L.

When Predators Avoid Predation by Their Con- and Heterospecific Competitors: Non-consumptive Effects Mediate Foraging Behavior and Prey Handling Time of Predators.

Aphids show highly aggregated distributions, and thus their predators tend to aggregate as well, creating conditions optimal to consumptive and non-consumptive (N-CEs) effects among competing predators, both conspecific and heterospecific. If predatory larvae are themselves potential prey for other predators, they may be also sensitive to N-CEs imposed by their con- or heterospecifics. A partitioned Petri-dish that permitted the passage of visual and chemical signals was used to examine the N-CEs of predator on foraging behavior of other predators, as prey themselves.

Differences in Flight Activity of Coleomegilla maculata and Hippodamia convergens (Coleoptera: Coccinellidae) Following Emergence, Mating, and Reproduction.

The flight activity of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) was examined by observing tethered beetles in the laboratory. C. maculata were fed eggs of Ephestia kuehniella Zeller, as were larval H.

Egg Cannibalism and its Life History Consequences Vary with Life Stage, Sex, and Reproductive Status in Hippodamia convergens (Coleoptera: Coccinellidae).

Egg cannibalism is common in Coccinellidae, but its biological consequences have not been fully explored. We examined egg cannibalism by neonates, fourth instars, and adults of Hippodamia convergens Guerin-Meneville for effects on development, reproduction, and progeny fitness. We also tested female adults for ability to avoid cannibalizing their own eggs and first-instar larvae, and both sexes for changes in cannibalism propensity following mating, all in the presence of ad libitum food [larvae: eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), adults: Schizaphis graminum (Rondani)].

Comparative Life Histories of Greenbugs and Sugarcane Aphids (Hemiptera: Aphididae) Coinfesting Susceptible and Resistant Sorghums.

Host-plant resistance has been a fundamental component of aphid management in cereal crops. Over decades, various sources of resistance to greenbug, Schizaphis graminum (Rondani), were bred into cultivars of sorghum, Sorghum bicolor (L.) Moench, to counter recurring virulent greenbug biotypes.

Host plant mediates foraging behavior and mutual interference among adult Stethorus gilvifrons (Coleoptera: Coccinellidae) preying on Tetranychus urticae (Acari: Tetranychidae).

Physical plant characteristics can influence predator foraging and their behavioral responses to each other. This study examined the searching efficiency and functional response of adult female Stethorus gilvifrons Mulsant foraging for Tetranychus urticae Koch (Acari: Tetranychidae) on castor bean, common bean, and cucumber leaves. Experiments conducted on leaf discs in arenas for 12 h revealed a type II functional response for S.

Foraging behavior of the coccinellid Nephus includens (Coleoptera: Coccinellidae) in response to Aphis gossypii (Hemiptera: Aphididae) with particular emphasis on larval parasitism.

This study assessed the effect of parasitism of Nephus includens (Col.: Coccinellidae) larvae by Homalotylus flaminius (Hym.: Encyrtidae) on the predation rates of the predator on the cotton aphid, Aphis gossypii Glover (Hem.