Zelus renardii, commonly known as the leaf hopper assassin bug,[1][2] is a predacious insect contained within tribe Harpactorini.

[3] Diurnal and found on both wild and crop plants, Z. renardii has spread from its native habitats in western North and Central America into three other biogeographic regions across the globe.

[4] Zelus renardii is considered a sister species to Z. cervicalis, as they share two unique characters: the lateral margins of dorsal phallothecal sclerite are recurved, and the medial process is strongly hooked apically.

[5] The native range of Z. renardii extends over various climatic zones throughout mainland North and Central America at altitudes between 8m to 2000m above sea level.

[2] To date, Z. renardii has expanded to Hawaii, where they preyed mainly on invasive sugarcane leafhopper (Perkinsiella saccharicida)[2] and other tropical areas within the Pacific, such as Johnston Atoll, Samoa, and the Philippines.

[2] However, expansion has continued and Z. renardii is now known in multiple countries in the Mediterranean basin, such as France,[7] Italy,[8] Turkey and Albania.

[2][6] Disturbed and agricultural areas are suitable for Z. renardii and may also contribute to its spread throughout native and non-native regions once established.

[4] 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.

[4] Distinguishing it from other Zelus species, the scutellum is long and bears no projections and the last ventral abdominal segment is slender with a hooked median process apically.

[11] But if the male approaches from the front and female is receptive, there is a short precopulatory period where both sexes stridulate by rubbing their rostra against prosternal grooves.

This is accomplished through the deposition of sticky substances with the egg masses, which helps mitigate threats and increase survival of the young.

[1] 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.

[3] 1st instars typically initiate application of these substances 25 minutes post-hatching in order to improve predation success and substrate adhesion.

[3] Additionally, sticky substances on their middle and/or hindlegs provides better adhesion to substrates, like plant surface, which is important for ambushing and handling struggling prey.

The rapid liquifaction of prey items is thought to be due to proteinase enzymes produced by the salivary glands and injected in the saliva by the stylet.

As the ingested material moves to the posterior midgut and hindgut, it is now composed of shortened peptide chains, which allows exopeptidases to continue hydrolysis.

Endopeptidase activity in the salivary glands and anterior midgut and exopeptidase activity in the posterior midgut and hindgut is thought to be an adaptation to acquiring food from a mainly solid form as it allows decreased prey handling time and decreases time of vulnerability during feeding.

[14] As Z. renardii feeds on many herbivorous pest species of cotton, maize, soybean, alfalfa, and fruit tree crops,[2][12] it can be considered a biological control agent.

[4][12] 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).