Morphology, Life Stages, and Longevity of a New Report of Stenocranus near pseudopacificus (Kirkaldy) in Kalinga, Philippines

Abstract

A new report of Stenocranus near pseudopacificus Kirkaldy is documented as an insect pest of corn in Kalinga, Luzon, Philippines. As the identification of this insect species was done only again in the first quarter of 2021, work understanding its biology and life history is in its infancy compared to other planthoppers with corn as the primary plant host, which may share similar genome organization and vectorial capacity to transmit phytopathogens. Very little knowledge is known regarding its biological and ecological characteristics. Here, the number of nymphal stages of S. nr. pseudopacificus – as well as its longevity on corn – were determined. Morphological identification of S. nr. pseudopacificus indicated that these planthoppers have whitish vertex slightly broader in the apex, reddish-brown band between median and lateral carinae running down to the frons, and similar built and yellow-orange coloration to S. pacificus Kirkaldy except in genitalia. To check for the longevity and life stages of S. nr. pseudopacificus Kirkaldy a total of 150 macropterous adults were collected from a local corn field in Tabuk City, Kalinga. Results showed that S. nr. pseudopacificus has four nymphal stages. Moreover, the incubation period of eggs was 11–12 d, first nymphal (N1) stage lasted for 4-–5 d, 3–6 d for the second nymphal stage (N2), 6–7 d for the third nymphal stage (N3), 2–6 d for fourth nymphal stage (N4), and 9–13 d for the adult stage. Based on these results, it was found that S. nr. pseudopacificus completes its life cycle, excluding its egg incubation period, from 24–37 d. The results of this study provided relevant new information about this species’ life-history traits. Its presence in the key corn planting region of the country merits further data and survey collection for its impact on corn production.