Factors Altering the Temporal and Within-Plant Distribution of Coccinellids in Corn and Their Impact on Potential Intra-guild Predation

The multicolored Asian ladybeetle Harmonia axyridis (Coleoptera: Coccinellidae) in Quebec agroecosystems ten years after its arrival

“…However, our study showed the continued presence of the indigenous C. maculata along with the three introduced ladybeetles in each agroecosystem examined. Coleomegilla maculata is found on the lower parts of corn plants and avoids competition with H. axyridis which is found on the upper parts of plants (Musser & Shelton, 2003). As a result of this niche partitioning, C. maculata is able to coexist with H. axyridis in corn fields, suggesting that this species may not suffer adversely from the presence of these invasive species in the future.…”

“…Brown & Miller (1998) and Lucas et al (2002) showed that a species may be more susceptible to impact by an invader than other species because of their common spatial niche in the ecosystem. Other indigenous species such as C. maculata were thought to be affected by the presence of H. axyridis (Musser & Shelton, 2003;Hoogendoorn & Heimpel, 2004). However, our study showed the continued presence of the indigenous C. maculata along with the three introduced ladybeetles in each agroecosystem examined.…”

Suitability of pollen sources for the development and reproduction of Coleomegilla maculata (Coleoptera: Coccinellidae) under simulated drought conditions

“…For 7 example, Pfannenstiel and Yeargan (2002) concluded that the availability of 8 sweet corn pollen during anthesis reduced predation of Helicoverpa zea eggs by 9 C. maculata, similar to the conclusion of Cottrell and Yeargan (1998). On the 10 other hand, the presence of pollen as an alternative food source has been 11 postulated to ameliorate intraguild predation between C. maculata and Harmonia 12 axyridis Pallas and promote their co-existence in corn fields, presumably 13 facilitating improved biological control (Musser and Shelton, 2003 growth chamber at a constant temperature of 24 ± 2 ºC under 'cool-white' 5 fluorescent lights set to 18 h day length. Relative humidity averaged 42 ± 5 % 6 throughout the course of experiments.…”

Asymmetric larval interactions between introduced and indigenous ladybirds in North America

“…Common in Asia (e.g., Takahashi 1989;Yasuda and Shinya 1997), CS and HA now occur throughout North America (e.g., Maredia et al 1992;Tedders and Schaefer 1994;LaMana and Miller 1996;Brown and Miller 1998;Colunga-Garcia and Gage 1998;Lucas et al 2002;Musser and Shelton 2003;Nault and Kennedy 2003). HA larvae are stronger intraguild predators than CS larvae in Japan (Takahashi 1989;Yasuda and Shinya 1997;Sato et al 2003), and HA larvae also appear more able to exploit coleopteran (vs. aphid) prey than are larvae of CS (Yasuda and Ohnuma 1999;Kalaskar and Evans 2001).…”