Leafhopper Assassin Bug

There appears to be no pattern of host-plant preference in Z. renardii, as it can be caught while beating and sweeping both flowering and non-flowering vegetation. Z. renardii is also common in agricultural and even urban and suburban environments. Zelus renardii also exhibits different vertical distributions depending on age. Nymphs occupied and foraged on lower parts of plants, whereas adults spent most of their time in the upper parts of plants, which may be a mechanism to avoid either competition between individuals or cannibalism. These differences in microhabitats may affect prey encounter rates.

Adult and nymph Z. renardii are zoophagous generalist predators which feed on a wide range of prey, from herbivorous insects that feed on wild and crop plants to other insect predators, like lacewings. Nymphs mainly feed on herbivorous insects between 0.5 and 4mm in length, such as aphids, weevils, and thrips, whereas adults feed on larger prey items between 1.5 and 19 mm in length from various orders, including Hemiptera, Lepidoptera, Coleoptera, Hymenoptera, Neuroptera, Blattodea, and Orthoptera. Since Z. renardii feeds on such a wide variety of prey, its diet may shift under different ecological conditions or between habitats which have different prey composition and abundance. Although Z. renardii is a predaceous insect, the 1st and 2nd instars may utilize some plant material, such as pollen or nectar from extrafloral nectaries on the bottom of leaves or fruiting structures, as a supplement to their regular zoophagous diet or to sustain them for short periods when more suitable prey is not available. Zelus renardii is also an important intraguild predator of lacewings and other insect predators. Z. renardii shows changes in prey preferences across developmental stages which influences the relevance of intraguild predation. The intensity of intraguild predation on other predators increases with the age of Z. …

As Z. renardii feeds on many herbivorous pest species of cotton, maize, soybean, alfalfa, and fruit tree crops, it can be considered a biological control agent. However, even though prey items of Z. renardii are often considered pests in an agricultural context, some beneficial species that are also used as biological control in agricultural systems are preyed upon. Due to its generalist diet, Z. renardii can function as an important intraguild predator on arthropods, such as the lacewing Chrysoperla carnea, which is commonly used to control cotton aphids (Aphis gossypii). As it consumes herbivorous pests and other predators of that pest, it can disrupt the trophic cascades that the biological control agent is being used to impose in anthropogenic systems, and can indirectly cause the abundance of the pest to rise. This affect may be prevented if Z. renardii's preference for the other predator is low relative to its preference for the shared prey.