The Impact of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) on Control of Dysmicoccus neobrevipes Beardsley (Hemiptera: Pseudococcidae)

摘要

Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) is an important predator of the mealybug Dysmicoccus neobrevipes (Hemiptera: Pseudococcidae), a major pest of Agave sisalana in China. Limited reports on the efficacy of C. montrouzieri against D. neobrevipes are available. This study reports the predatory efficacy and functional response of C. montrouzieri against D. neobrevipes under laboratory conditions. The prey consumption rate per day of 4th instar larvae of C. montrouzieri feeding on 1st instar D. neobrevipes nymphs (241.3 mealybugs) was the highest among the different larval life stages of the beetle. For C. montrouzieri , the prey consumption per day of adult females (19.8 mealybugs) was significantly higher compared to males (15.2 mealybugs) when feeding on 3rd instar D. neobrevipes nymphs. The functional responses of C. montrouzieri on 1st and 2nd instar D. neobrevipes nymphs were determined as Holling type II. The search rates of C. montrouzieri 4th instar larvae towards the 1st and 2nd instar nymphs of D. neobrevipes were higher than those of the other beetle life stages. In addition, the handling times of 4th instar larvae were shorter than those of the other beetle life stages. The results from this study indicate that C. montrouzieri can be used as a predator of D. neobrevipes and, therefore, it should be evaluated further for use as a biocontrol agent in D. neobrevipes management programs.