Euplectrus comstockii

Howard, 1880

Euplectrus comstockii is an ectoparasitoid in the Eulophidae that parasitizes larval Lepidoptera. females inject venom containing a developmental arrestant that arrests molting and , maintaining the host in a suitable state for offspring development. The has been studied extensively for its host-parasitoid interactions, venom biochemistry, and potential use in programs. Developmental timing varies with temperature: at 24°C and 72.8% relative humidity, the stage lasts approximately 1.75 days, larval stage 5.0 days, 0.95 days, and pupa 5.5 days.

Pronunciation

How to pronounce Euplectrus comstockii: /juːˈplɛktrəs kɒmˈstɒki.aɪ/

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Identification

Euplectrus comstockii can be distinguished from the closely related E. plathypenae by morphological and chemical differences; specific diagnostic features require detailed examination. As an ectoparasitoid, females can be observed ovipositing on the exterior of larvae rather than within host tissues.

Distribution

Recorded from Alabama, Arizona, Arkansas, Connecticut, and District of Columbia in the United States.

Diet

feed on sugar solutions; larvae are ectoparasitoids that feed externally on larvae.

Host Associations

Anticarsia gemmatalis - primary velvetbean caterpillar, main pest of soybean in Colombia; fourth instar larvae preferred for oviposition
Trichoplusia ni - cabbage looper; parasitized larvae show premature production of late larval
Heliothis virescens - tobacco budworm; developmental response to dietary ascorbic acid documented
Diatraea saccharalis - non-sugarcane borer; larvae not parasitized

Life Cycle

At 24°C and 72.8% relative humidity, mean developmental duration is: 1.75 days, larva 5.0 days, 0.95 days, pupa 5.5 days. female longevity 10–32 days, male longevity 7–14 days when fed sugar solution. Sex ratio female:male approximately 4:1. Maximum egg production observed: 75 eggs over 20 days.

Behavior

females inject venom containing a developmental arrestant that arrests molting and , preventing the host from developing beyond a stage suitable for offspring. Parasitized host larvae typically cease feeding 4–5 days after parasitization.

Ecological Role

Ectoparasitoid of lepidopteran larvae; contributes to natural of agricultural pest , particularly in soybean systems.

Human Relevance

Studied as a potential agent for agricultural pests including the velvetbean caterpillar (Anticarsia gemmatalis), a major soybean pest. Mass rearing protocols have been investigated for programs.

Similar Taxa

Euplectrus plathypenaecongeneric ectoparasitoid with overlapping range; distinguished by morphological and chemical characteristics
Euplectrus puttlericongeneric named in honor of researcher Ben Puttler; also parasitizes Anticarsia gemmatalis in South America

More Details

Venom biochemistry

The venom contains a developmental arrestant that alters , stimulating premature production of late larval normally found only in final instar larvae. This demonstrates the venom's ability to manipulate host developmental physiology independently of the host's endocrine system.

Cold storage limitations

Storage of mature pupae at 5–6°C and 75% relative humidity for more than one week negatively affects , mating success, longevity, and vigor, limiting options for stockpiling agents.

Host suitability mechanisms

protein composition differs between permissive and non-permissive , suggesting biochemical factors influence host- compatibility.