Extremely Long-Closed Galls of a Social Aphid

Utako Kurosu,Shigeyuki Aoki

doi:10.1155/2009/159478

Abstract

The aphidNipponaphis monzeni(Hormaphidinae, Nipponaphidini) forms large, hard, completely closed galls on the evergreenDistylium racemosum, its primary host, in south-western Japan. By marking 100 galls on a tree and monitoring them over five years, and by sampling many immature galls from another tree in various seasons and dissecting them, we found that galls ofN. monzeniare initiated in June, that they remain small for at least 21–22 months and that tiny fundatrices survive for over one year. Some galls rapidly expand during April/May in the third year. Others remain small and swell up in the fourth year and still others in the fifth year. Full-grown galls open in November/December, and alates fly to evergreen oaks, the secondary host. Thus galls ofN. monzenitake 2.5 years to mature at earliest (3-year life cycle) and some galls 3.5 or 4.5 years (4- or 5-year life cycle).

Highlights

Aphid galls formed on a tree wither and die within the year [1], but a few exceptions have been reported from the subfamily Hormaphidinae. It takes longer than one year for galls of Tuberaphis styraci (Cerataphidini) to mature on the temperate deciduous Styrax obassia [2]
Nipponaphis distyliicola (Nipponaphidini), on the evergreen Distylium racemosum, forms completely closed galls that remain small over several months and rapidly expand in the following spring [4]
These sexuparae were collected from a colony on a tree of Quercus glauca in Atsugi, Kanagawa Prefecture, and from another colony on a tree of Q. myrsinaefolia in Niiza, both of which had been established by the introduction of many alates from 18 galls of N. monzeni to the oak trees

Summary

Introduction

Aphid galls formed on a tree wither and die within the year [1], but a few exceptions have been reported from the subfamily Hormaphidinae. It takes longer than one year for galls of Tuberaphis styraci (Cerataphidini) to mature on the temperate deciduous Styrax obassia [2]. Nipponaphis distyliicola (Nipponaphidini), on the evergreen Distylium racemosum, forms completely closed galls that remain small over several months and rapidly expand in the following spring [4]. Galls of some other cerataphidines may last for over one year [5,6,7]. We found extremely long-lasting galls in the Nipponaphidini, which remain closed for at least two and a half years

Objectives

Methods

Results

Conclusion